A large data center can include large numbers of workloads (e.g., virtual machines) executing on hardware hosts. In such a scenario, it is often of interest to know if and to what extent a group of hardware hosts can host additional workloads. The accuracy of estimates made simply considering unused hardware resources, e.g., CPU cycles, is often unsatisfactory. Capacity planning tools can be used to provide reliable estimates of the ability of a group of hardware hosts to handle more workloads, but can consume more resources than desirable in providing the estimate. What is needed is a less resource intensive approach for accurately estimating the capacity of a group of hosts to handle additional workloads.